Software for processing a database query that includes: (i) receiving a query of a database including a search value; (ii) determining a distance between the search value and at least one reference value; (iii) determining a maximum distance from the search value to be used in searching a plurality of datasets of the database, wherein the maximum distance from the search value defines a search range and is based, at least in part, on the determined distance between the search value and the at least one reference value; (iv) determining a subset of datasets from the plurality of datasets that includes datasets for which a data range with respect to each reference value overlaps with the search range; and (v) performing approximate string matching for the search value on the subset of datasets.